Critical Care Medicine-Neurologic Disorders>>>>>Mechanical Ventilation
Question 10#

A 48-year-old man with no prior medical history is admitted with community-acquired pneumonia and severe acute respiratory distress syndrome (ARDS). On day 1 of his illness, he is admitted to your ICU on:

volume control-assist control ventilation with a VT of 4 mL/kg IBW

• respiratory rate 32 breaths per minute
• PEEP 14 cm H₂O
• FiO₂ 1.0

On those settings, he is found to be hypoxemic with a SaO₂ of 86% with an ABG that demonstrates:

• pH 7.28 PCO₂ 65 mm Hg
• PaO₂ 55 mm Hg

Which of the following interventions is most likely to improve his survival?

A. Prone positioning for at least 16 hours a day until oxygenation improves
B. Initiation of extracorporeal membrane support (ECMO)
C. PEEP titration using esophageal balloon pressures
D. Initiation of high-frequency oscillatory ventilation
E. Inhaled pulmonary vasodilator therapy

Correct Answer is A

Comment:

Correct Answer: A

Although prior data were conflicting, a recent large, multicenter randomized controlled study of prone positioning in patients with ARDS within the first 48 hours demonstrated a significant reduction in mortality in the prone position group (answer A is correct). Although ECMO is increasingly employed as a rescue therapy in patients with severe ARDS and refractory hypoxemia, there have been no trials that demonstrate a significant mortality benefit (answer B is incorrect). PEEP titration using an esophageal balloon improves oxygenation and pulmonary mechanics in patients with ARDS but does not improve mortality. High-frequency oscillatory ventilation has been shown to potentially harm patients with ARDS (answer D is incorrect). Although inhaled pulmonary vasodilators improve oxygenation in patients with ARDS, there are not data that they improve survival (answer E is incorrect).

References:

1. Guerin C, Reignier J, Richards JC, et al. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med. 2013;368:2159-2168.
2. Combes A, Hajage D, Capellier G, et al. Extracorporeal membrane oxygenation for severe acute respiratory distress syndrome. N Engl J Med. 2018;378:1965-1975.
3. Beitler JR, Sarge T, Banner-Godspeed VM, et al. Effect of titrating positive end-expiratory pressure (PEEP) With an Esophageal pressure–guided strategy vs an empirical high PEEP-Fio₂ strategy on death and days free from mechanical ventilation among patients with acute respiratory distress syndrome. JAMA. 2019;321:846-857.
4. Gebistorf F, Karam O, Wetterslev J, Afshari A. Inhaled nitric oxide for acute respiratory distress syndrome (ARDS) in children and adults. Cochrane Database Syst Rev. 2016;(6):CD002787.